Biaxially textured articles formed by powder metallurgy

ABSTRACT

A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100}&lt;100&gt; orientation texture; and further having a Curie temperature less than that of pure Ni.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 09/931,514 entitled Biaxially Textured Articles Formed byPowder Metallurgy, filed on Aug. 16, 2001 now U.S. Pat. No. 6,602,313hereby incorporated by reference, which is a divisional application ofU.S. patent application Ser. No. 09/570,289 entitled Biaxially TexturedArticles Formed by Powder Metallurgy, filed on May 15, 2000, whichissued as U.S. Pat. No. 6,331,199 on Dec. 18, 2001, hereby incorporatedby reference.

The following relate to the present invention and are herebyincorporated by reference: U.S. patent application Ser. No. 09/571,561Method for Forming Biaxially Textured Articles by Powder Metallurgy byGoyal, filed on May 15, 2000; U.S. Pat. No. 5,739,086 Structures HavingEnhanced Biaxial Texture and Method of Fabricating Same by Goyal et al.,issued Apr. 14, 1998; U.S. Pat. No. 5,741,377 Structures Having EnhancedBiaxial Texture and Method of Fabricating Same by Goyal et al., issuedApr. 21, 1998; U.S. Pat. No. 5,898,020 Structures Having biaxial Textureand Method of Fabricating Same by Goyal et al., issued Apr. 27, 1999;U.S. Pat. No. 5,958,599 Structures Having Enhanced Biaxial Texture byGoyal et al., issued Sep. 28, 1999; U.S. Pat. No. 5,964,966 Method ofForming Biaxially Textured Substrates and Devices Thereon by Goyal etal., issued Oct. 21, 1999; and U.S. Pat. No. 5,968,877 High Tc YBCOSuperconductor Deposited on Biaxially Textured Ni Substrate by Budai etal., issued Oct. 19, 1999.

This invention was made with Government support under Contract No.DE-AC05-960R22464 awarded by the United States Department of Energy. TheGovernment has certain rights in this invention.

FIELD OF THE INVENTION

The present invention relates to biaxially textured metallic substratesand articles made therefrom, and more particularly to such substratesand articles made from high purity face-centered cubic (FCC) materialsusing powder metallurgy techniques to form long lengths of biaxiallytextured sheets, and more particularly to the use of said biaxiallytextured sheets as templates to grow epitaxial metal/alloy/ceramiclayers.

BACKGROUND OF THE INVENTION

Current materials research aimed at fabricating high-temperaturesuperconducting ceramics in conductor configurations for bulk, practicalapplications, is largely focused on powder-in-tube methods. Such methodshave proved quite successful for the Bi—(Pb)—Sr—Ca—Cu—O (BSCCO) familyof superconductors due to their unique mica-like mechanical deformationcharacteristics. In high magnetic fields, this family of superconductorsis generally limited to applications below 30K. In the Re—Ba—Cu—O(ReBCO, Re denotes a rare earth element), Tl—(Pb,Bi)—Sr—(Ba)—Ca—Cu—O andHg—(Pb)—Sr—(Ba)—Ca—Cu—O families of superconductors, some of thecompounds have much higher intrinsic limits and can be used at highertemperatures.

It has been demonstrated that these superconductors possess highcritical current densities (J_(c)) at high temperatures when fabricatedas single crystals or in essentially single-crystal form as epitaxialfilms on single crystal substrates such as SrTiO₃ and LaAlO₃. Thesesuperconductors have so far proven intractable to conventional ceramicsand materials processing techniques to form long lengths of conductorwith J_(c) comparable to epitaxial films. This is primarily because ofthe “weak-link” effect.

It has been demonstrated that in ReBCO, biaxial texture is necessary toobtain high transport critical current densities. High J_(c)'s have beenreported in polycrystalline ReBCO in thin films deposited on specialsubstrates on which a biaxially textured non-superconducting oxidebuffer layer is first deposited using ion-beam assisted deposition(IBAD) techniques. IBAD is a slow, expensive process, and difficult toscale up for production of lengths adequate for many applications.

High J_(c)'s have also been reported in polycrystalline ReBCOmelt-processed bulk material which contains primarily small angle grainboundaries. Melt processing is also considered too slow for productionof practical lengths.

Thin-film materials having perovskite-like structures are important insuperconductivity, ferroelectrics, and electro-optics. Many applicationsusing these materials require, or would be significantly improved by,single crystal, c-axis oriented perovskite-like films grown onsingle-crystal or highly aligned metal or metal-coated substrates.

For instance, Y—Ba₂—Cu₃—O_(X) (YBCO) is an important superconductingmaterial for the development of superconducting current leads,transmission lines, motor and magnetic windings, and other electricalconductor applications. When cooled below their transition temperature,superconducting materials have no electrical resistance and carryelectrical current without heating up. One technique for fabricating asuperconducting wire or tape is to deposit a YBCO film on a metallicsubstrate. Superconducting YBCO has been deposited on polycrystallinemetals in which the YBCO is c-axis oriented, but not aligned in-plane.To carry high electrical currents and remain superconducting, however,the YBCO films must be biaxially textured, preferably c-axis oriented,with essentially no large-angle grain boundaries, since such grainboundaries are detrimental to the current-carrying capability of thematerial. YBCO films deposited on polycrystalline metal substrates donot generally meet this criterion.

The present invention provides a method for fabricating biaxiallytextured sheets of alloy substrates with desirable compositions. Thisprovides for applications involving epitaxial devices on such alloysubstrates. The alloys can be thermal expansion and lattice parametermatched by selecting appropriate compositions. They can then beprocessed according to the present invention, resulting in devices withhigh quality films with good epitaxy and minimal microcracking.

The terms “process”, “method”, and “technique” are used interchangeablyherein.

For further information, refer to the following publications:

-   1. K. Sato, et al., “High-J_(c) Silver-Sheathed Bi-Based    Superconducting Wires”, IEEE Transactions on Magnetics, 27 (1991)    1231.-   2. K. Heine, et al., “High-Field Critical Current Densities in    Bi₂Sr₂Ca₁Cu₂O_(8+x)/Ag Wires”, Applied Physics Letters, 55 (1991)    2441.-   3. R. Flukiger, et al., “High Critical Current Densities in    Bi(2223)/Ag tapes”, Superconductor Science & Technology 5, (1992)    S61.-   4. D. Dimos et al., “Orientation Dependence of Grain-Boundary    Critical Currents in Y₁Ba₂Cu₃O_(7−x) Bicrystals”, Physical Review    Letters, 61 (1988) 219.-   5. D. Dimos et al., “Superconducting Transport Properties of Grain    Boundaries in Y₁Ba₂Cu₃O₇ Bicrystals”, Physical Review B, 41 (1990)    4038.-   6. Y. Iijima, et al., “Structural and Transport Properties of    Biaxially Aligned YBa₂Cu₃O_(7−x) Films on Polycrystalline Ni-Based    Alloy with Ion-Beam Modified Buffer Layers”, Journal of Applied    Physics, 74 (1993) 1905.-   7. R. P. Reade, et al. “Laser Deposition of biaxially textured    Yttria-Stabilized Zirconia Buffer Layers on Polycrystalline Metallic    Alloys for High Critical Current Y—Ba—Cu—O Thin Films”, Applied    Physics Letters, 61 (1992) 2231.-   8. D. Dijkkamp et al., “Preparation of Y—Ba—Cu Oxide Superconducting    Thin Films Using Pulsed Laser Evaporation from High Tc Bulk    Material,” Applied Physics Letters, 51, 619 (1987).-   9. S. Mahajan et al., “Effects of Target and Template Layer on the    Properties of Highly Crystalline Superconducting a-Axis Films of    YBa₂Cu₃O_(7−x) by DC-Sputtering,” Physica C, 213, 445 (1993).-   10. A. Inam et al., “A-axis Oriented Epitaxial    YBa₂Cu₃O_(7−x)—PrBa₂Cu₃O_(7−x) Heterostructures,”Applied Physics    Letters, 57, 2484 (1990).-   11. R. E. Russo et al., “Metal Buffer Layers and Y—Ba—Cu—O Thin    Films on Pt and Stainless Steel Using Pulsed Laser Deposition,”    Journal of Applied Physics, 68, 1354 (1990).-   12. E. Narumi et al., “Superconducting YBa₂Cu₃O_(6.8) Films on    Metallic Substrates Using In Situ Laser Deposition,” Applied Physics    Letters, 56, 2684 (1990).-   13. R. P. Reade et al., “Laser Deposition of Biaxially Textured    Yttria-Stabilized Zirconia Buffer Layers on Polycrystalline Metallic    Alloys for High Critical Current Y—Ba—Cu—O Thin Films,” Applied    Physics Letters, 61, 2231 (1992).-   14. J. D. Budai et al., “In-Plane Epitaxial Alignment of    YBa₂Cu₃O_(7−x) Films Grown on Silver Crystals and Buffer Layers,”    Applied Physics Letters, 62, 1836 (1993).-   15. T. J. Doi et al., “A New Type of Superconducting Wire; Biaxially    Oriented Tl₁(Ba_(0.8)Sr_(0.2))₂Ca₂Cu₃O₉ on {100}<100> Textured    Silver Tape,” Proceedings of 7th International Symposium on    Superconductivity, Fukuoka, Japan, Nov. 8-11, 1994.-   16. D. Forbes, Executive Editor, “Hitachi Reports 1-meter Tl-1223    Tape Made by Spray Pyrolysis”, Superconductor Week, Vol. 9, No. 8,    Mar. 6, 1995.-   17. Recrystallization, Grain Growth and Textures, Papers presented    at a Seminar of the American Society for Metals, Oct. 16 and 17,    1965, American Society for Metals, Metals Park, Ohio.

OBJECTS OF THE INVENTION

Accordingly, it is an object of the present invention to provide new anduseful biaxially textured metallic substrates and articles madetherefrom.

It is another object of the present invention to provide such biaxiallytextured metallic substrates and articles made therefrom by rolling andrecrystallizing high purity face-centered cubic materials to form longlengths of biaxially textured sheets.

It is yet another object of the present invention to provide for the useof said biaxially textured sheets as templates to grow epitaxialmetal/alloy/ceramic layers.

Further and other objects of the present invention will become apparentfrom the description contained herein.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, the foregoingand other objects are achieved by a biaxially textured alloy articlehaving a magnetism less than pure Ni which comprises a rolled andannealed compacted and sintered powder-metallurgy preform article, thepreform article having been formed from a powder mixture selected fromthe group of binary mixtures consisting of: between 99 at % and 80 at %Ni powder and between 1 at % and 20 at % Cr powder; between 99 at % and80 at % Ni powder and between 1 at % and 20 at % W powder; between 99 at% and 80 at % Ni powder and between 1 at % and 20 at % V powder; between99 at % and 80 at % Ni powder and between 1 at % and 20 at % Mo powder;between 99 at % and 60 at % Ni powder and between 1 at % and 40 at % Cupowder; between 99 at % and 80 at % Ni powder and between 1 at % and 20at % Al powder; the article having a fine and homogeneous grainstructure; and having a dominant cube oriented {100}<100> orientationtexture; and further having a Curie temperature less than that of pureNi.

In accordance with a second aspect of the present invention, theforegoing and other objects are achieved by a biaxially textured alloyarticle having a magnetism less than pure Ni which comprises a rolledand annealed compacted and sintered powder-metallurgy preform article,the preform article having been formed from a powder mixture selectedfrom the group of ternary mixtures consisting of: Ni powder, Cu powder,and Al powder; Ni powder, Cr powder, and Al powder; Ni powder, W powderand Al powder; Ni powder, V powder, and Al powder; Ni powder, Mo powder,and Al powder; the article having a fine and homogeneous grainstructure; and having a dominant cube oriented {100}<100> orientationtexture; and further having a Curie temperature less than that of pureNi.

In accordance with a third aspect of the present invention, theforegoing and other objects are achieved by a biaxially textured alloyarticle alloy article having a magnetism less than pure Ni whichcomprises a rolled and annealed compacted and sintered powder-metallurgypreform article, the preform article having been formed from a powdermixture selected from the group of mixtures consisting of: at least 60at % Ni powder and at least one of Cr powder, W powder, V powder, Mopowder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, and REpowder; the article having a fine and homogeneous grain structure; andhaving a dominant cube oriented {100}<100> orientation texture; andfurther having a Curie temperature less than that of pure Ni.

In accordance with a fourth aspect of the present invention, theforegoing and other objects are achieved by a strengthened, biaxiallytextured alloy article having a magnetism less than pure Ni whichcomprises a rolled and annealed, compacted and sinteredpowder-metallurgy preform article, the preform article having beenformed from a powder mixture selected from the group of mixturesconsisting of: Ni, Ag, Ag—Cu, Ag—Pd, Ni—Cu, Ni—V, Ni—Mo, Ni—Al,Ni—Cr—Al, Ni—W—Al, Ni—V—Al, Ni—Mo—Al, Ni—Cu—Al; and at least one finepowder such as but not limited to Al₂O₃, MgO, YSZ, CeO₂, Y₂O_(3,), andYSZ; the article having a grain size which is fine and homogeneous andfurther having a dominant cube oriented {100}<100> orientation texture;and further having a Curie temperature less than that of pure Ni.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 shows a (111) pole figure for a Ni-9 at % W alloy fabricated byrolling and annealing a compacted and sintered, powder metallurgypreform. The pole figure indicates only four peaks consistent with onlya well-developed {100}<100>, biaxial cube texture. The final annealingtemperature of the sample was 1200° C.

FIG. 2 shows a phi (φ) scan of the [111] reflection, with φ varying from0° to 360°, for a Ni-9 at % W alloy fabricated by rolling and annealinga compacted and sintered, powder metallurgy preform. The presence offour peaks is with only a well-developed {100}<100>, biaxial cubetexture is apparent. The final annealing temperature of the sample was1200° C. The FWHM of the φ-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜8.8°. The FWHM of the peaks in this scanis indicative of the in-plane texture of the grains in the sample.

FIG. 3 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked in the rolling direction, for a Ni-9 at % W alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜6.1°.

FIG. 4 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked about the rolling direction, for a Ni-9 at % W alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜8.5°.

FIG. 5 shows a (111) pole figure for a Ni-9 at % W alloy fabricated byrolling and annealing a compacted and sintered, powder metallurgypreform. The pole figure indicates only four peaks consistent with onlya well-developed {100}<100>, biaxial cube texture. The final annealingtemperature of the sample was 1400° C.

FIG. 6 shows a phi (φ) scan of the [111] reflection, with φ varying from0° to 360°, for a Ni-9 at % W alloy fabricated by rolling and annealinga compacted and sintered, powder metallurgy preform. The presence offour peaks is with only a well-developed {100}<100>, biaxial cubetexture is apparent. The final annealing temperature of the sample was1400° C. The FWHM of the φ-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜5.8°. The FWHM of the peaks in this scanis indicative of the in-plane texture of the grains in the sample.

FIG. 7 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked in the rolling direction, for a Ni-9 at % W alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜4.3°.

FIG. 8 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked about the rolling direction, for a Ni-9 at % W alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.4°.

FIG. 9 shows a (111) pole figure for a Ni-13 at % Cr alloy fabricated byrolling and annealing a compacted and sintered, powder metallurgypreform. The pole figure indicates only four peaks consistent with onlya well-developed {100}<100>, biaxial cube texture. The final annealingtemperature of the sample was 1200° C.

FIG. 10 shows a phi (φ) scan of the [111] reflection, with φ varyingfrom 0° to 360°, for a Ni-13 at % Cr alloy fabricated by rolling andannealing a compacted and sintered, powder metallurgy preform. Thepresence of four peaks is with only a well-developed {100}<100>, biaxialcube texture is apparent. The final annealing temperature of the samplewas 1200° C. The FWHM of the φ-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜8.7°. The FWHM of the peaks in this scanis indicative of the in-plane texture of the grains in the sample.

FIG. 11 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked in the rolling direction, for a Ni-13 at % Cr alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜5.8°.

FIG. 12 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked about the rolling direction, for a Ni-13 at % Cr alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜9.8°.

FIG. 13 shows a (111) pole figure for a Ni-13 at % Cr alloy fabricatedby rolling and annealing a compacted and sintered, powder metallurgypreform. The pole figure indicates only four peaks consistent with onlya well-developed {100}<100>, biaxial cube texture. The final annealingtemperature of the sample was 1400° C.

FIG. 14 shows a phi (φ) scan of the [111] reflection, with φ varyingfrom 0° to 360°, for a Ni-13 at % Cr alloy fabricated by rolling andannealing a compacted and sintered, powder metallurgy preform. Thepresence of four peaks is with only a well-developed {100}<100>, biaxialcube texture is apparent. The final annealing temperature of the samplewas 1400° C. The FWHM of the φ-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜6.1°. The FWHM of the peaks in this scanis indicative of the in-plane texture of the grains in the sample.

FIG. 15 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked in the rolling direction, for a Ni-13 at % Cr alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜4.5°.

FIG. 16 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked about the rolling direction, for a Ni-13 at % Cr alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.3°.

FIG. 17 shows a (111) pole figure for a Ni-0.03 at % Mg alloy fabricatedby rolling and annealing a compacted and sintered, powder metallurgypreform. The Mg is predominantly expected to be present as MgO. The polefigure indicates only four peaks consistent with only a well-developed{100}<100>, biaxial cube texture. The final annealing temperature of thesample was 1200° C.

FIG. 18 shows a phi (φ) scan of the [111] reflection, with φ varyingfrom 0° to 360°, for a Ni-0.03 at % Mg alloy fabricated by rolling andannealing a compacted and sintered, powder metallurgy preform. Thepresence of four peaks is with only a well-developed {100}<100>, biaxialcube texture is apparent. The final annealing temperature of the samplewas 1200° C. The FWHM of the φ-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.7°. The FWHM of the peaks in this scanis indicative of the in-plane texture of the grains in the sample.

FIG. 19 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked in the rolling direction, for a Ni-0.03 at % Mg alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.8°.

FIG. 20 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked about the rolling direction, for a Ni-0.03 at % Mg. Thefinal annealing temperature of the sample was 1200° C. The peak isindicative of the out-of-plane texture of the sample. The FWHM of theω-scan, as determined by fitting a gaussian curve to one of the peaks is˜9.2°.

FIG. 21 shows a (111) pole figure for a Ni-9 at % W-0.03at % Mg alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The Mg is predominantly expected to be present asMgO. The pole figure indicates only four peaks consistent with only awell-developed {100}<100>, biaxial cube texture. The final annealingtemperature of the sample was 1200° C.

FIG. 22 shows a phi (φ) scan of the [111] reflection, with φ varyingfrom 0° to 360°, for a Ni-9 at % W-0.03% Mg alloy fabricated by rollingand annealing a compacted and sintered, powder metallurgy preform. Thepresence of four peaks is with only a well-developed {100}<100>, biaxialcube texture is apparent. The final annealing temperature of the samplewas 1200° C. The FWHM of the φ-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜9.1°. The FWHM of the peaks in this scanis indicative of the in-plane texture of the grains in the sample.

FIG. 23 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked in the rolling direction, for a Ni-9 at % W-0.03% Mg alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The final annealing temperature of the sample was1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.2°.

FIG. 24 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked about the rolling direction, for a Ni-9 at % W-0.03 at % Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜9.1°.

FIG. 25 shows a (111) pole figure for a Ni-9 at % W-0.03 at % Mg alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The Mg is predominantly expected to be present asMgO. The pole figure indicates only four peaks consistent with only awell-developed {100}<100>, biaxial cube texture. The final annealingtemperature of the sample was 1400° C.

FIG. 26 shows a phi (φ) scan of the [111] reflection, with φ varyingfrom 0° to 360°, for a Ni-9 at % W-0.03 at % Mg alloy fabricated byrolling and annealing a compacted and sintered, powder metallurgypreform. The presence of four peaks is with only a well-developed{100}<100>, biaxial cube texture is apparent. The final annealingtemperature of the sample was 1400° C. The FWHM of the φ-scan, asdetermined by fitting a gaussian curve to one of the peaks is ˜6.1°. TheFWHM of the peaks in this scan is indicative of the in-plane texture ofthe grains in the sample.

FIG. 27 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked in the rolling direction, for a Ni-9 at % W-0.03 at % Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜6.7°.

FIG. 28 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked about the rolling direction, for a Ni-9 at % W-0.03 at % Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.5°.

FIG. 29 shows a (111) pole figure for a Ni-13 at % Cr-0.03 at % Mg alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The Mg is predominantly expected to be present asMgO. The pole figure indicates only four peaks consistent with only awell-developed {100}<100>, biaxial cube texture. The final annealingtemperature of the sample was 1200° C.

FIG. 30 shows a phi (φ) scan of the [111] reflection, with φ varyingfrom 0° to 360°, for a Ni-13 at % Cr-0.03 at % Mg alloy fabricated byrolling and annealing a compacted and sintered, powder metallurgypreform. The presence of four peaks with only a well-developed{100}<100>, biaxial cube texture is apparent. The final annealingtemperature of the sample was 1200° C. The FWHM of the φ-scan, asdetermined by fitting a gaussian curve to one of the peaks is ˜8.1°. TheFWHM of the peaks in this scan is indicative of the in-plane texture ofthe grains in the sample.

FIG. 31 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked in the rolling direction, for a Ni-13 at % Cr-0.03 at % Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜5.1°.

FIG. 32 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked about the rolling direction, for a Ni-13 at % Cr-0.03 at %Mg alloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1200° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜9.5°.

FIG. 33 shows a (111) pole figure for a Ni-13 at % Cr-0.03 at % Mg alloyfabricated by rolling and annealing a compacted and sintered, powdermetallurgy preform. The Mg is predominantly expected to be present asMgO. The pole figure indicates only four peaks consistent with only awell-developed {100}<100>, biaxial cube texture. The final annealingtemperature of the sample was 1400° C.

FIG. 34 shows a phi (φ) scan of the [111] reflection, with φ varyingfrom 0° to 360°, for a Ni-13 at % Cr-0.03 at % Mg alloy fabricated byrolling and annealing a compacted and sintered, powde metallurgypreform. The presence of four peaks is with only a well-developed{100}<100>, biaxial cube texture is apparent. The final annealingtemperature of the sample was 1400° C. The FWHM of the φ-scan, asdetermined by fitting a gaussian curve to one of the peaks is ˜6.5°. TheFWHM of the peaks in this scan is indicative of the in-plane texture ofthe grains in the sample.

FIG. 35 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked in the rolling direction, for a Ni-13 at % Cr-0.03 at % Mgalloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜6.9°.

FIG. 36 shows a rocking curve (ω-scan) from 10° to 40° with the samplebeing rocked about the rolling direction, for a Ni-13 at % Cr-0.03 at %Mg alloy fabricated by rolling and annealing a compacted and sintered,powder metallurgy preform. The final annealing temperature of the samplewas 1400° C. The peak is indicative of the out-of-plane texture of thesample. The FWHM of the ω-scan, as determined by fitting a gaussiancurve to one of the peaks is ˜7.9°.

DETAILED DESCRIPTION OF THE INVENTION

Note: As used herein, percentages of components in compositions areatomic percent unless otherwise specified.

A new method for producing highly textured alloys has been developed. Itis well established in the art that high purity FCC metals can bebiaxially textured under certain conditions of plastic deformation, suchas rolling, and subsequent recrystallization. For example, a sharp cubetexture can be attained by deforming Cu by large amounts (90%) followedby recrystallization. However, this is possible only in high purity Cu.Even small amounts of impurity elements (i.e., 0.0025% P, 0.3% Sb, 0.18%Cd, 0.47% As, 1% Sn, 0.5% Be etc.) can significantly modify thedeformation behavior and hence the kind and amount of texture thatdevelops on deformation and recrystallization. In this invention, amethod is described to texture alloys of cubic materials, in particularFCC metal based alloys. Alloys and composite compositions resulting indesirable physical properties can be processed to form long lengths ofbiaxially textured sheets. Such sheets can then be used as templates togrow epitaxial metal/alloy/ceramic layers for a variety of applications.

The present invention has application especially in the making ofstrengthened substrates with magnetism less than that of pure Ni. For asubstance to have less magnetism than pure Ni implies that its Curietemperature is less than that of pure Ni. Curie temperature is known inthe art as the temperature at which a metal becomes magnetic. In thefollowing description, a material having less magnetism than that ofpure Ni implies a material having a Curie temperature at least 50° C.less than that of pure Ni.

Many device applications require good control of the grain boundary ofthe materials comprising the device. For example in high temperaturesuperconductors grain boundary character is very important. The effectsof grain boundary characteristics on current transmission across theboundary have been very clearly demonstrated for Y123. For clean,stochiometric boundaries, J_(c)(gb), the grain boundary criticalcurrent, appears to be determined primarily by the grain boundarymisorientation. The dependence of J_(c)(gb) on misorientation angle hasbeen determined by Dimos et al. [1] in Y123 for grain boundary typeswhich can be formed in epitaxial films on bicrystal substrates. Theseinclude [001] tilt, [100] tilt, and [100] twist boundaries [1]. In eachcase high angle boundaries were found to be weak-linked. The low J_(c)observed in randomly oriented polycrystalline Y123 can be understood onthe basis that the population of low angle boundaries is small and thatfrequent high angle boundaries impede long-range current flow. Recently,the Dimos experiment has been extended to artificially fabricated [001]tilt bicrystals in Tl₂Ba₂CaCu₂O_(X)[2], Tl₂Ba₂Ca₂Cu₃O_(X)[3],TlBa₂Ca₂Cu₂O_(X)[4], and Nd_(1.85)Ce_(0.15)CuO₄[3]. In each case it wasfound that, as in Y123, J_(c) depends strongly on grain boundarymisalignment angle. Although no measurements have been made on Bi-2223,data on current transmission across artificially fabricated grainboundaries in Bi-2212 indicate that most large angle [001] tilt [3] andtwist [5,6] boundaries are weak links, with the exception of somecoincident site lattice (CSL) related boundaries [5,6]. It is likelythat the variation in J_(c) with grain boundary misorientation inBi-2212 and Bi-2223 is similar to that observed in thewell-characterized cases of Y123 and Tl-based superconductors. Hence inorder to fabricate high temperature superconductors with very criticalcurrent densities, it is necessary to biaxially align essentially allthe grains. This has been shown to result in significant improvement inthe superconducting properties of YBCO films [7-10].

A method for producing biaxially textured substrates was taught inprevious U.S. Pat. Nos. 5,739,086, 5,741,377, 5,898,020, and 5,958,599.That method relies on the ability to texture metals, in particular FCCmetals such as copper, to produce a sharp cube texture followed byepitaxial growth of additional metal/ceramic layers. Epitaxial YBCOfilms grown on such substrates resulted in high J_(c). However, in orderto realize any applications, one of the areas requiring significantimprovement and modification is the nature of the substrate. Thepreferred substrate was made by starting with high purity Ni, which isfirst thermomechanically biaxially textured, followed by epitaxialdeposition of metal and/or ceramic layers. Because Ni is ferromagnetic,the substrate as a whole is magnetic and this causes difficulty inpractical applications involving superconductors. A second problem isthe thermal expansion mismatch between the preferred substrate and theoxide layers. The thermal expansion of the substrate is dominated bythat of Ni which is quite different from most desired ceramic layers forpractical applications. This mismatch can result in cracking and maylimit properties. A third problem is the limitation of the latticeparameter to that of Ni alone. If the lattice parameter can be modifiedto be closer to that of the ceramic layers, epitaxy can be obtained farmore easily with reduced internal stresses. This can reduce or preventcracking and other stress-related defects and effects (e.g.delamination) in the ceramic films.

Although a method to form alloys starting from the textured Ni substrateis also suggested in U.S. Pat. Nos. 5,739,086, 5,741,377, 5,898,020, and5,958,599, its scope is limited in terms of the kinds of alloys that canbe fabricated. This is because only a limited set of elements can behomogeneously diffused into the textured Ni substrate.

A method for fabricating textured alloys was proposed in anotherprevious invention U.S. Pat. No. 5,964,966. The invention involved theuse of alloys of cubic metals such as Cu, Ni, Fe, Al and Ag for makingbiaxially textured sheets such that the stacking fault frequency, υ, ofthe alloy with all the alloying additions is less than 0.009. In case itis not possible to make an alloy with desired properties to have thestacking fault frequency less than 0.009 at room temperature, thendeformation can be carried out at higher temperatures where the υ isless than 0.009. However, that invention may be limited in the sharpnessof the texture which can be attained. This is because no specificcontrol on the starting material to fabricate the biaxially texturedalloys was given which results in a sharp biaxial texture. Moreover, thealloys fabricated using the methods described in the invention, resultin materials which have secondary recrystallization temperatures lessthan 1200° C. Once the secondary recrystallization temperature isreached, the substrate essentially begins to lose all its cube texture.Low secondary recrystallization temperatures limit the sharpness ofbiaxial texture that can be obtained and what deposition temperaturescan be used for depositing epitaxial oxide or other layers on suchsubstrates.

Furthermore, the invention does not teach how one could potentiallytexture and effectively use an alloy with compositions such that thestacking fault frequency of the alloy is greater than 0.009 at roomtemperature. Lastly, the invention does not provide a method or describean article which effectively incorporates ceramic constituents in thealloy body to result in very significant mechanical toughening, yetmaintaining the strong biaxial texture.

A metallic object such as a metal tape is defined as having a cubetexture when the [100} crystallographic planes of the metal are alignedparallel to the surface of the tape and the [100] crystallographicdirection is aligned along the length of the tape. The cube texture isreferred to as the {100}<100> texture.

Here, a new method for fabricating strongly or dominantly cube texturedsurfaces of composites which have tailored bulk properties (i.e. thermalexpansion, mechanical properties, non-magnetic nature, etc.) for theapplication in question, and which have a strongly textured surface thatis compatible with respect to lattice parameter and chemical reactivitywith the layers of the electronic device(s) in question, is described.Herein the term dominantly or strongly cube textured surface describesone that has 95% of the grains comprising the surface in the {100}<100>orientation.

oriented The method for fabricating biaxially textured alloys of theherein disclosed and claimed invention utilizes powder metallurgytechnology. Powder metallurgy allows fabrication of alloys withhomogeneous compositions everywhere without the detrimental effects ofcompositional segregation commonly encountered when using vacuum meltingor casting to make alloys. Furthermore, powder metallurgy allows easycontrol of the grain size of the starting alloy body. Moreover, powdermetallurgy allows a fine and homogeneous grain size to be achieved.Herein, fine grain size means grain size less than 200 microns.Homogeneous grain size means variation in grain size of less than 40%.In the following we break the discussion into three parts:

Procedures and examples to obtain biaxially textured alloys which havestacking fault frequencies less than 0.009 at room temperature, but havebetter biaxial textures and have higher secondary recrystallizationtemperatures.

Procedures and examples to obtain biaxially textured alloys with adistribution of ceramic particles for mechanical strengthening.

Procedures and examples to obtain and effectively use biaxially texturedalloys which have stacking fault frequencies greater than 0.009 at roomtemperature.

Procedures and Examples to Obtain Biaxially Textured Alloys which haveStacking Frequencies Less than 0.009 at Room Temperature, but haveBetter Biaxial Textures and have Higher Secondary RecrystallizationTemperatures

The basic premise or idea here is that alloys are formed by startingwith high purity powders of the alloy constituents, mechanically mixingthem together to form a homogeneous mixture, compacting andheat-treating the resulting body to form a raw article or startingpreform. The thermomechanical treatment results in a fine andhomogeneous grain size in the initial starting preform.

EXAMPLE I

Begin with a mixture of 80% Ni powder (99.99% purity) and 9% W powder.Mix and compact at appropriate pressures into a rod or billet. Then heattreat at 900° C. for 2 hr. The grain size at the end of heat treatmentis less than 50 μm. Deform, by rolling, to a degree greater than 90%total deformation, preferably using 10% reduction per pass and byreversing the rolling direction during each subsequent pass. Anneal atabout 1200° C. for about 60 minutes to produce a sharp biaxial texture.Annealing is performed in flowing 4% H₂ in Ar.

FIG. 1 shows a (111) X-ray diffraction pole figure of the biaxiallytextured alloy substrate. As can be seen, only four peaks are evident.Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 2 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapeis determined by fitting a gaussian curve to the data is ˜8.8°. FIG. 3shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 3 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 6.14°. FIG. 4 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 8.49°. This is truly asingle orientation texture with all crystallographic axis being alignedin all direction within 8-9° Alloys made by procedures other than whatis described above result in secondary recrystallization at about 1200°C.

EXAMPLE II

Begin with a mixture of 80% Ni powder (99.99% purity) and 9% W powder.Mix and compact at appropriate pressures into a rod or billet. Then heattreat at 900° C. for 2 hr. The grain size at the end of heat treatmentis less than 50 μm. Deform, by rolling, to a degree greater than 90%total deformation, preferably using 10% reduction per pass and byreversing the rolling direction during each subsequent pass. Anneal atabout 1400° C. for about 60 minutes to produce a sharp biaxial texture.Annealing is performed in flowing 4% H₂ in Ar.

FIG. 5 shows a (111) X-ray diffraction pole figure of the biaxiallytextured alloy substrate. As can be seen, only four peaks are evident.Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 6 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapeis determined by fitting a gaussian curve to the data is ˜6.3°. FIG. 7shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 7 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 6.7°. FIG. 8 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 7.5°. This is truly asingle orientation texture with all crystallographic axis being alignedin all direction within 6-7° Alloys made by procedures other than whatis described above result in secondary recrystallization at temperaturesmuch below 1400° C. and do not result in single orientation cube textureas shown in the pole figure of FIG. 5.

EXAMPLE III

Begin with a mixture of 87 at % Nickel powder (99.99% purity) and 13%Chromium powder. Mix and compact at appropriate pressures into a rod orbillet. Then heat treat at 900° C. for 2 hr. The grain size at the endof heat treatment is less than 50 □m. Deform, by rolling, to a degreegreater than 90% total deformation, preferably using 10% reduction perpass and by reversing the rolling direction during each subsequent pass.Anneal at about 1200° C. for about 60 minutes to produce a sharp biaxialtexture. Annealing is performed in flowing 4% H₂ in Ar.

FIG. 9 shows a (111) X-ray diffraction pole figure of the biaxiallytextured alloy substrate. As can be seen, only four peaks are evident.Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 10 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapedetermined by fitting a gaussian curve to the data is ˜8.68°. FIG. 11shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 11 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 5.83°. FIG. 12 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 9.82°. This is truly asingle orientation texture with all crystallographic axis being alignedin all directions within 8-10°. Alloys made by procedures other thanwhat is described above result in secondary recrystallization at 1200°C.

EXAMPLE IV

Begin with a mixture of 87 at % Nickel powder (99.99% purity) and 13%Chromium powder. Mix and compact at appropriate pressures into a rod orbillet. Then heat treat at 900° C. for 2 hr. The grain size at the endof heat treatment is less than 50 □m. Deform, by rolling, to a degreegreater than 90% total deformation, preferably using 10% reduction perpass and by reversing the rolling direction during each subsequent pass.Anneal at about 1400° C. for about 60 minutes to produce a sharp biaxialtexture. Annealing is performed in flowing 4% H₂ in Ar.

FIG. 13 shows a (111) X-ray diffraction pole figure of the biaxiallytextured alloy substrate. As can be seen, only four peaks are evident.Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 14 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapedetermined by fitting a gaussian curve to the data is ˜6.1°. FIG. 15shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 15 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 4.5°. FIG. 16 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 7.3°. This is truly asingle orientation texture with all crystallographic axis being alignedin all directions within 6-7°. Alloys made by procedures other than thewhat is described above result in secondary recrystallization attemperatures much below 1400° C. and do not result in single orientationcube texture as shown in the pole figure of FIG. 13.

Similar experiments can be performed with binary alloys of Ni—Cu, Ni—V,Ni—Mo, Ni—Al, and with ternary alloys of Ni—Cr—Al, Ni—W—Al, Ni—V—Al,Ni—Mo—Al, Ni—Cu—Al. Similar results are also expected for 100% Ag and Agalloys such Ag—Cu, Ag—Pd.

Procedures and Examples to Obtain Biaxially-Textured Alloys with aDistribution of Ceramic Particles for Mechanical Strengthening

Conventional wisdom and numerous experimental results indicate thathard, ceramic particles are introduced or dispersed within a metal oralloy it results in significant mechanical strengthening. This arisesprimarily due to enhanced defect or dislocation generation should thismaterial be deformed. Conventional wisdom and prior experimental resultsalso indicate because of the presence of such hard, ceramic particles,and the enhanced defect generation locally at these particles, thedeformation is very inhomogeneous. Inhomogeneous deformation essentiallyprevents the formation of any sharp crystallographic texture. Hence,conventional wisdom and prior experimental results show that thepresence of even a very small concentration of ceramic particles resultin little texture formation even in high purity FCC metals such as Cuand Ni. Here we provide a method where ceramic particles can beintroduced in a homogeneous fashion to obtain mechanical strengtheningof the substrate, and still obtain a high degree of biaxial texture. Thekey is to have a particle size of less than 1 μm and uniformdistribution of the ceramic particles in the final preform, prior to thefinal rolling to obtain biaxial texture.

EXAMPLE V

Begin with a mixture of 0.03 at % Mg and remaining Ni powder. Mix andcompact at appropriate pressures into a rod or billet. Then heat treatat 900° C. for 2 hr. During this thermomechanical processing all the Mgis converted to MgO and it is dispersed in a fine and homogeneous mannerthroughout the preform. The grain size at the end of heat treatment isless than 50 □m. Deform, by rolling, to a degree greater than 90% totaldeformation, preferably using 10% reduction per pass and by reversingthe rolling direction during each subsequent pass. Anneal at about 1200°C. for about 60 minutes to produce a sharp biaxial texture. Annealing isperformed in flowing 4% H₂ in Ar.

FIG. 17 shows a (111) X-ray diffraction pole figure of the biaxiallytextured, particulate, composite substrate. As can be seen, only fourpeaks are evident. Each peak refers to one of four crystallographicallysimilar orientations corresponding to {100}<100>, such that the (100)plane is parallel to the surface of the tape and <100> direction isaligned along the long axis of the tape. FIG. 18 shows a phi-scan of the[111] reflection showing the degree of in-plane texture. The FWHM of thetape determined by fitting a gaussian curve to the data is ˜8.68°. FIG.19 shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 19 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 7.92°. FIG. 20 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 9.20°. This is truly asingle orientation texture with all crystallographic axis being alignedin all directions within 8-10°.

Alloy substrates made by procedures other than what is described aboveundergo secondary recrystallization at such annealing temperatures andlose most of their biaxial texture. On the contrary, the substratesreported here improve their biaxial textures upon annealing attemperatures as high as 1400° C.

EXAMPLE VI

Begin with a mixture of 0.03 at % Mg, 9 at % W and remaining Ni powder.Mix and compact at appropriate pressures into a rod or billet. Then heattreat at 900° C. for 2 hr. During this thermomechanical processing allthe Mg is converted to MgO and it is dispersed in a fine, andhomogeneous manner throughout the preform. The grain size at the end ofheat treatment is less than 50 □m. Deform, by rolling, to a degreegreater than 90% total deformation, preferably using 10% reduction perpass and by reversing the rolling direction during each subsequent pass.Anneal at about 1200° C. for about 60 minutes to produce a sharp biaxialtexture. Annealing is performed in flowing 4% H₂ in Ar.

FIG. 21 shows a (111) X-ray diffraction pole figure of the biaxiallytextured, particulate, composite substrate. As can be seen, only fourpeaks are evident. Each peak refers to one of four crystallographicallysimilar orientations corresponding to {100}<100>, such that the (100)plane is parallel to the surface of the tape and <100> direction isaligned along the long axis of the tape. FIG. 22 shows a phi-scan of the[111] reflection showing the degree of in-plane texture. The FWHM of thetape determined by fitting a gaussian curve to the data is ˜9.05°. FIG.23 shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 23 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 7.2°. FIG. 24 is a rocking curve with the sample being rockedabout the rolling direction and shows a FW of 9.04°. This is truly asingle orientation texture with all crystallographic axis being alignedin all directions within 8-10°. Alloy substrates made by proceduresother than what is described above undergo secondary recrystallizationat such annealing temperatures and lose most of their biaxial texture.On the contrary, the substrates reported here improve their biaxialtextures upon annealing at temperatures as high as 1400° C.

EXAMPLE VII

Begin with a mixture of 0.03 at % Mg, 9 at % W and remaining Ni powder(99.99% purity). Mix and compact at appropriate pressures into a rod orbillet. Then heat treat at 900° C. for 2 hr. During thisthermomechanical processing all the Mg is converted to MgO and it isdispersed in a fine and homogeneous manner throughout the preform. Thegrain size at the end of heat treatment is less than 50 μm. Deform, byrolling, to a degree greater than 90% total deformation, preferablyusing 10% reduction per pass and by reversing the rolling directionduring each subsequent pass. Anneal at about 1400° C. for about 60minutes to produce a sharp biaxial texture. Annealing is performed inflowing 4% H₂ in Ar.

FIG. 25 shows a (111) X-ray diffraction pole figure of the biaxiallytextured alloy substrate. As can be seen, only four peaks are evident.Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 26 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapeis determined by fitting a gaussian curve to the data is ˜6.1°. FIG. 27shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 27 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 6.7°. FIG. 28 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 7.5°. This is truly asingle orientation texture with all crystallographic axis being alignedin all direction within 6-7°. Alloy substrates made by procedures otherthan what is described above undergo secondary recrystallization at suchannealing temperatures and lose most of their biaxial texture. On thecontrary, the substrates reported here, improve their biaxial texturesupon annealing at temperatures as high as 1400° C.

EXAMPLE VIII

Begin with a mixture of 0.03 at % Mg, 13 at % Cr and remaining Nipowder. Mix and compact at appropriate pressures into a rod or billet.Then heat treat at 900° C. for 2 hr. During this thermomechanicalprocessing all the Mg is converted to MgO and it is dispersed in a fineand homogeneous manner throughout the preform. The grain size at the endof heat treatment is less than 50 μm. Deform, by rolling, to a degreegreater than 90% total deformation, preferably using 10% reduction perpass and by reversing the rolling direction during each subsequent pass.Anneal at about 1200° C. for about 60 minutes to produce a sharp biaxialtexture. Annealing is performed in flowing 4% H₂ in Ar.

FIG. 29 shows a (111) X-ray diffraction pole figure of the biaxiallytextured, particulate, composite substrate. As can be seen, only fourpeaks are evident. Each peak refers to one of four crystallographicallysimilar orientations corresponding to {100}<100>, such that the (100)plane is parallel to the surface of the tape and <100> direction isaligned along the long axis of the tape. FIG. 30 shows a phi-scan of the[111] reflection showing the degree of in-plane texture. The FWHM of thetape determined by fitting a gaussian curve to the data is ˜8.06°. FIG.31 shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 31 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 5.1°. FIG. 32 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 9.47°. This is truly asingle orientation texture with all crystallographic axis being alignedin all directions within 8-10°. Begin with a mixture of 0.03 at % Mg, 9at % W and remaining Ni powder (99.99% purity). Mix and compact atappropriate pressures into a rod or billet. Then heat treat at 900° C.for 2 hr. During this thermomechanical processing all the Mg isconverted to MgO and it is dispersed in a fine and homogeneous mannerthroughout the preform. The grain size at the end of heat treatment isless than 50 μm. Deform, by rolling, to a degree greater than 90% totaldeformation, preferably using 10% reduction per pass and by reversingthe rolling direction during each subsequent pass. Anneal at about 1400°C. for about 60 minutes to produce a sharp biaxial texture. Annealing isperformed in flowing 4% H₂ in Ar.

EXAMPLE IX

Begin with a mixture of 0.03at % Mg, 13 at % Cr and remaining Ni powder(99.99% purity). Mix and compact at appropriate pressures into a rod orbillet. Then heat treat at 900° C. for 2 hr. During thisthermomechanical processing all the Mg is converted to MgO and it isdispersed in a fine and homogeneous manner throughout the preform. Thegrain size at the end of heat treatment is less than 50 μm. Deform, byrolling, to a degree greater than 90% total deformation, preferablyusing 10% reduction per pass and by reversing the rolling directionduring each subsequent pass. Anneal at about 1400° C. for about 60minutes to produce a sharp biaxial texture. Annealing is performed inflowing 4% H₂ in Ar.

FIG. 33 shows a (111) X-ray diffraction pole figure of the biaxiallytextured alloy substrate. As can be seen, only four peaks are evident.Each peak refers to one of four crystallographically similarorientations corresponding to {100}<100>, such that the (100) plane isparallel to the surface of the tape and <100> direction is aligned alongthe long axis of the tape. FIG. 34 shows a phi-scan of the [111]reflection showing the degree of in-plane texture. The FWHM of the tapeis determined by fitting a gaussian curve to the data is ˜6.5°. FIG. 35shows the rocking curve or the out-of-plane texture as measured byscanning the [200] reflection of the substrate. FIG. 35 is a rockingcurve with the sample being rocked in the rolling direction and shows aFWHM of 6.9°. FIG. 36 is a rocking curve with the sample being rockedabout the rolling direction and shows a FWHM of 7.9°. This is truly asingle orientation texture with all crystallographic axis being alignedin all direction within 6-8°. Alloy substrates made by procedures otherthan what is described above undergo secondary recrystallization at suchannealing temperatures and lose most of their biaxial texture. On thecontrary, the substrates reported here, improve their biaxial texturesupon annealing at temperatures as high as 1400° C.

EXAMPLE X

Begin with 99.99% pure Ni powder, and mix in fine (nanocrystalline ormicrocrystalline) oxide powders such as CeO₂, Y₂O₃, and the like. Mixhomogeneously and compact to a monolithic form. Deform, preferably byreverse rolling to a degree of deformation greater than 90%. Heat treatat temperatures above the primary recrystallization temperature butbelow the secondary recrystallization temperature to obtain a sharpbiaxially textured substrate.

Similar experiments with additions of a dispersion and at least one finemetal oxide powder such as but not limited to Al₂O₃, MgO, YSZ, CeO₂,Y₂O_(3,), YSZ, and RE₂O₃; etc. can be performed with binary alloys ofNi—Cu, Ni—V, Ni—Mo, Ni—Al, and with ternary alloys of Ni—Cr—Al, Ni—W—Al,Ni—V—Al, Ni—Mo—Al, Ni—Cu—Al. Similar results are also expected for 100%Ag and Ag alloys such Ag—Cu, Ag—Pd.

Procedures and Examples to Obtain and Effectively use Biaxially TexturedAlloys which have Stacking Fault Frequencies Greater than 0.009 at RoomTemperature

In all the following examples, begin with separate powders of theconstituents required to form the alloy, mixing them thoroughly andcompacting them preferably into the form or a rod or billet. The rod orbillet is then deformed, preferably by rolling, at about roomtemperature or a higher temperature provided the higher temperature islow enough that negligible inter-diffusion of elements occurs. Duringthe initial stages of deformation the larger metal constituentessentially forms a connected and mechanically bonded network. The rodor billet is now rolled to a large degree of deformation, preferablygreater than 90%. The alloying element powders remain as discreteparticles in the matrix and may not undergo any significant deformation.Once the deformation is complete, rapidly thermally re-crystallize thesubstrate to texture the matrix material. The alloying elements can bediffused in at a higher temperature after the texture is attained in thematrix.

EXAMPLE XI

Begin with 80% Ni and 20% Cr powder. Mix homogeneously and compact to amonolithic form. Heat-treat to low temperatures so as to bond Ni—Niparticles. Since Cr particles are completely surrounded by Ni, theirsintering or bonding to the Ni particles is not critical. Deform,preferably by reverse rolling to a degree of deformation greater than90%. In such a case, the final substrate does not have a homogeneouschemical composition. There are clearly Cr particles dispersed in thematrix. The substrate is now rapidly heated in a furnace to atemperature between the primary and secondary recrystallization of Ni.The objective is to obtain a cube texture in the Ni matrix, with localregions of high Cr concentrations. The aim of the heat treatment is tominimize diffusion of Cr into the Ni matrix. Once the cube texture hasbeen obtained, desired epitaxial oxide, nitride or other buffer layersare deposited on the substrate. Once the first layer is deposited, thesubstrate can be heat treated at higher temperatures to affect diffusionof Cr into Ni. While high concentrations of Cr of 20 at % in thesubstrate would result in appearance of secondary texture components, itdoes not matter at this point what the texture of the underlying metalbelow the textured ceramic buffer layer is, since further epitaxy isgoing to occur at the surface of the first-ceramic layer.

Similar experiments can be performed with binary alloys of Ni—Cu, Ni—V,Ni—Mo, Ni—Al, and with ternary alloys of Ni—Cr—Al, Ni—W—Al, Ni—V—Al,Ni—Mo—Al, Ni—Cu—Al. Similar results are also expected for 100% Ag and Agalloys such Ag—Cu, Ag—Pd.

Similar experiments can also be performed with additions of a dispersionof at least one fine metal oxide powder such as but not limited toAl₂O₃, MgO, YSZ, CeO₂, Y₂O_(3,), YSZ, and RE₂O₃; etc. with binary alloysof Ni—Cu, Ni—V, Ni—Mo, Ni—Al, and with ternary alloys of Ni—Cr—Al,Ni—W—Al, Ni—V—Al, Ni—Mo—Al, Ni—Cu—Al. Similar results are also expectedfor 100% Ag and Ag alloys such Ag—Cu, Ag—Pd.

While there has been shown and described what are at present consideredthe preferred embodiments of the invention, it will be obvious to thoseskilled in the art that various changes and modifications can be madetherein without departing from the scope of the inventions defined bythe appended claims.

1. A biaxially textured alloy article having a magnetism less than pureNi comprising a rolled and annealed compacted and sinteredpowder-metallurgy preform article, the preform article having beenformed from a powder mixture selected from the group of ternary mixturesconsisting of: Ni powder, Cu powder, and Al powder; Ni powder, Crpowder, and Al powder; Ni powder, W powder and Al powder: Ni powder, Vpowder, and Al powder; Ni powder, Mo powder, and Al powder; said alloyarticle having a stacking fault frequency greater than 0.009 at roomtemperature; said alloy article having a fine and homogeneous grainstructure; said alloy article having a dominant cube oriented {100}<100>orientation texture; said alloy article further having a Curietemperature less than that of pure Ni; said alloy article furthercomprising at least one layer having superconducting properties.
 2. Abiaxially textured alloy article in accordance with claim 1 furthercomprising a dispersion of at least one metal oxide.